1. Field of the Invention
The present invention is directed to a torsional vibration damper with a drive-side damper element and a driven-side damper element that is rotatable relative to the drive-side damper element against the action of a damping element.
2. Description of the Related Art
A prior art torsional vibration damper is disclosed in German reference DE 197 26 532 A1 with a drive-side damper element and a driven-side damper element. The driven-side damper element is rotatable relative to the drive-side element against the action of a damping device. The damping device transmits torque between the two damper elements and has a plurality of coupling bodies, each of which is received in at least one guide path of the drive-side damper element and in at least one guide path of the driven-side damper element. The coupling body comprises an outer circumference which engages one of the guide paths and a bearing neck which engages the other respective guide path. As is shown especially clearly in FIGS. 3, 10 or 12 of the prior art reference, all of the guide paths extend in each of the damper elements in a comparable manner. For example, in one damper element the guide paths are curved in an essentially semicircular manner at least in their radial outer rolling area for the coupling body and in the other damper element the guide paths extend substantially radially. The semicircular curved guide paths are constructed so as to extend farther in the circumferential direction than in the radial direction, while the other guide paths are constructed so as to extend farther in the radial direction than in the circumferential direction. The following problem results from this prior art arrangement:
FIGS. 10 and 12 of the prior art reference show that only very slender webs remain between every two guide paths in all guide paths which are constructed so as to extend farther in the circumferential direction in a damper element. This problem occurs even when the quantity of guide paths in the circumferential direction is limited to a comparatively small number. However, the minimum width of these webs must be dimensioned such that the loads occurring on the damper element, e.g., shearing loads or bending loads, are withstood. At the same time, the extension of the guide paths in the circumferential direction is determined by the desired amount of deflection of the damper elements relative to one another. Accordingly, the quantity of coupling bodies to be received in this damper element is necessarily limited to a comparatively small number. It is precisely these coupling bodies that carry out the transmission of torque between the damper elements. Since a greater number of these coupling bodies is required to transmit high torques, the performance threshold of this type of prior art torsional vibration damper is relatively low. In the other damper element in which the guide paths run essentially radially, the webs between every two guide paths viewed in the circumferential direction are relatively very wide, especially when the guide paths which extend farther in the radial direction are to be provided for receiving the bearing necks of the coupling bodies which are often constructed with a smaller diameter than the outer circumference of the coupling bodies.